HCFC-22 is due to be phased out in certain countries for cooling and air conditioning applications to address Ozone Depletion Potential concerns related to that compound. Different replacement compositions for HCFC-22 (also known as R22) have been suggested, for example R417A which consists of 46.6 wt. % pentafluoroethane (HFC-125), 50 wt. % 1,1,1,2-tetrafluoroethane (HFC-134a) and 3.4 wt. % n-butane (R-600).
A specific field of application of HCFC-22 is low temperature refrigeration.
WO-A-01/23493 discloses a refrigerant composition comprising HFC-125, HFC-134a and an additive selected from a saturated hydrocarbon or a mixture thereof boiling in the range of −5 to 70° C. wherein the weights of HFC-125 to R134a is in the ranges 50-80 wt. % HFC-125, 50-20% wt % HFC-134a.
WO-A-2004/033582 discloses in particular compositions consisting of 85 wt. % HFC-125, 11.5 wt. % HFC-134a and 3.5 wt. % of n-butane or isobutane.